Technical Field
The disclosure relates to an inductor device and a method of manufacturing the same.
Related Art
In the related art, an inductor device that is to be used for a high-frequency circuit and the like of a variety of electronic devices has been known. A structure of the inductor device includes a wire winding type where an electric wire is wound, a plane type where a coil conductor having a spiral shape is formed on a plane, and the like.
[Patent Document 1] Japanese Patent Application Publication No. 2015-32625A
[Patent Document 2] Japanese Patent Application Publication No. 2015-32626A
[Patent Document 3] Japanese Patent Application Publication No. 2015-76597A
As described later in paragraphs of preliminary matters, in the inductor device, metal layers made of copper foils and formed on both surfaces of an insulating layer are connected to each other via a metal-plated layer formed in via holes of the insulating layer.
In the via structure, when thermal stress is generated, the stress is likely to be concentrated on the part of the insulating layer at an upper end of the via hole. For this reason, a crack is likely to be generated in the insulating layer and sufficient reliability of the via connection is not obtained.